def parse(tokens):
expr = RelationalExpression.parse(tokens)
if expr is None:
return None
while True:
peek = tokens.peek()
if peek == 'and' or peek == 'or':
tokens.getNext()
rhs = RelationalExpression.parse(tokens)
if rhs is None:
raise error.SyntaxError, 'Expected expression, got %r' % tokens.peek()
expr = LogicalExpression(expr, rhs, peek)
return expr
def testGreaterThanEqualTo(self):
tokens = lex('1 >= 2')
r = RelationalExpression.parse(tokens)
self.failUnless(isinstance(r,RelationalExpression), r)
def testNotEqualTo(self):
tokens = lex('1 != 2')
r = RelationalExpression.parse(tokens)
self.failUnless(isinstance(r,RelationalExpression), r)
def testLessThan(self):
tokens = lex('1 < 2')
r = RelationalExpression.parse(tokens)
self.failUnless(isinstance(r,RelationalExpression), r)